Summary of the invention
The object of this invention is to provide a kind of control method for bulldozer differential steering, to reduce turn radius, improve steering procedure can be handling.
Another object of the present invention is to provide a kind of control system of bulldozer differential steering, can realize small radius steering, and its structure is simple, turns to precision higher.
For solving the problems of the technologies described above, the invention provides a kind of control method of bulldozer differential steering, comprising the following steps:
11) receive turn sign, and obtain the current rotating speed of the motor driving bulldozer both sides vehicle wheel rotation respectively;
12) according to the size of described turn sign and current rotating speed calculate turn to time each motor needed for rotating speed of target;
13) each motor works according to each self-corresponding current rotating speed and rotating speed of target signal, performs differential steering action to make both sides wheel.
Control method of the present invention is according to the current rotating speed driven respectively corresponding to the motor of both sides vehicle wheel rotation and rotating speed of target work, thus make both sides wheel perform differential steering action, the moving velocity of both sides wheel can be effectively controlled in turning process, to reduce the uncontrollable factor in turning process, Servo Control precision is higher, turns to steadily; And compared to traditional steering mode, in this embodiment, both sides wheel is in motoring condition all the time when turning to, and namely makes PURE ROLLING, can save energy, also can turn to fast, neatly in Different Ground situation, and damage can not be caused to ground or wheel itself; Adopt power wheel differential steering, not easy to wear; Meanwhile, because the moving velocity of both sides wheel when turning and direction all can adjust, thus bulldozer can be made to work under low-speed big, to realize minor radius or even original place zero turn radius; Again, whole handling maneuver all realizes under the control of above-mentioned control method, and its intelligence degree is higher, and operation is more accurate, and what also can better meet operator turns to demand.
Preferably, described step 11) and step 12) between also comprise the steps:
111) detect speed-slackening signal, and judge whether to be in braking mode according to described speed-slackening signal, no, then perform step 12).
Because bulldozer only just can turn under non-brake state, therefore, before carrying out handling maneuver, first can detect its braking mode, to guarantee the safety turned to, avoid turning to and be obstructed, thus improve the logicality of control method.
Preferably, described step 111) and step 12) between also comprise the steps:
112) detect gear signal, if be in forward gear, then perform step 12); If be in backward gear, then reduce moving velocity, then perform step 12).
The requirement meeting difference to some extent turned under different range states, when bulldozer is in backward gear, first should reduce running velocity, can carry out safely and effectively to ensure to turn to, therefore, can arrange the step that gear detects, to improve the specific aim turned to.
Preferably, described step 11) and step 12) between also comprise the steps:
113) obtaining the moving velocity of bulldozer, and judge whether to be in stall condition according to the rotating speed of motor and moving velocity, is then stop, no, then perform step 13).
Preferably, described step 11) and step 12) between also comprise the steps:
114) judge that whether motor speed is controlled according to the rotating speed of motor, be, then perform step 13), no, then stop.
Before turning to, first can judge whether bulldozer is in stall condition or whether rotating speed is controlled, only when bulldozer is not in stall condition or its rotating speed is controlled, just perform handling maneuver, that is, for turning to, corresponding condition can be set to guarantee the safety turned to.
Preferably, described step 11) before there is following step:
10) prestore the activation threshold value turned to;
Described step 11) and step 12) between also there is following step:
115) judge whether the turn sign received is less than activation threshold value, is then return step 11), no, then perform step 12).
The method of activation threshold value can be adopted to judge whether to turn to, as long as compare the conclusion that can draw and whether turn to turn sign to activation threshold value, it is simple to operate, and reliability is higher.
The present invention also provides a kind of control system of bulldozer differential steering, and described control system comprises:
Drive the motor of bulldozer both sides vehicle wheel rotation respectively;
Revolution detector, for detecting the rotating speed of each motor;
Controller, for receiving turn sign and being connected with described revolution detector signal, to perform course changing control: the rotating speed of target calculating each motor according to the rotating speed of motor and turn sign, and export the instruction of each motor according to the rotating speed of target work of correspondence, perform differential steering action to make both sides wheel.
Control system of the present invention, its controller can calculate the rotating speed of target of motor according to the rotating speed of motor and turn sign, each motor drives both sides wheel to perform differential steering action according to the rotating speed of target of correspondence respectively, and its intelligence degree is higher; And handling maneuver can be performed according to the current state of bulldozer and turn sign, its real-time is comparatively strong, therefore the precision turned to is higher, and the controllable degree turned to is also higher; In addition, bulldozer has the motor driving both sides wheel respectively, each motor completes the driving to both sides wheel respectively, its specific aim is higher, to realize the distinguishing driving of both sides wheel, and then realizing minor-circle turn by the change in both sides wheels travel speed and direction, alerting ability and the convenience of its operation are all higher.
Preferably, prestore in described controller the activation threshold value turned to, and only when the turn sign received is not less than activation threshold value, performs course changing control.
Be pre-stored in by activation threshold value in controller, the size then by comparing turn sign and activation threshold value judges whether to perform course changing control, to improve the accuracy of turn sign.
Preferably, also comprise the braking mode detector be connected with described controller signals, described controller only receive when bulldozer is in the signal of non-brake state perform course changing control.This kind of setting can avoid internal system logical contradiction, reduces uncontrollable factor, improves the safety turned to.
Preferably, described control system comprises the gear detector be connected with described controller signals further, and when controller receives the signal of backward gear, described controller exports the instruction extremely described motor reducing the speed of a motor vehicle.Perform course changing control again after adjusting accordingly for different gears, can reduce and turn to risk, with the demand turned under adapting to different situations.
Preferably, control system also comprises the electrical fault detector be connected with described controller signals, and described electrical fault detector carries out fault detection to each motor.Increase fault detector and can carry out self-inspection to the fault of motor, to find fault timely and effectively and to correct, normally run with maintenance system, and the information of electrical fault detector can provide reference for whether being applicable to turning to.
Detailed description of the invention
Core of the present invention is to provide a kind of control method for bulldozer differential steering, to reduce turn radius, improve steering procedure can be handling.
Another core of the present invention is to provide a kind of control system of bulldozer differential steering, can realize small radius steering, and its structure is simple, turns to precision higher.
In order to make those skilled in the art person understand the present invention program better, below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.
Please refer to Fig. 1 and Fig. 2, Fig. 1 is the structured flowchart of control system provided by the present invention in a kind of detailed description of the invention; Fig. 2 is the diagram of circuit of control method provided by the present invention in a kind of detailed description of the invention.
Control system of the present invention comprises motor, the first motor 5 and the second motor 6 as shown in Figure 1.Control system also comprises turn signal detector 2, revolution detector and controller 1, and revolution detector comprises the first corresponding with the first motor 5 and the second motor 6 respectively motor speed sensor 52 and the second motor speed sensor 62.Wherein, the first motor 5 and the second motor 6 drive the wheel of bulldozer both sides to rotate respectively, and two motors can be arranged on the wheel of both sides respectively, also can be arranged on other positions.The motor number driving single wheel to rotate in this embodiment is one, can expect, when side has more than one driving wheel, all can configure motor for each driving wheel.First motor speed sensor 52 and the second motor speed sensor 62 detect the rotating speed of the first motor 5 and the second motor 6 respectively, and when motor number increases, the number of tachogen can correspondingly increase.
Controller 1 for receiving turn sign, such as, when bulldozer arranges electric control handle, operating personal controls to turn to by manipulation electric control handle, now, controller 1 can be connected with electric control handle signal, and the handling maneuver of operating personal is converted into turn sign and is passed to controller 1 by electric control handle.Controller 1 is also connected, to control turning to of bulldozer with the first motor speed sensor 52 and the second motor speed sensor 62 signal.
In literary composition, so-called signal connection refers to a kind of connection mode realizing signal transmission in wired or wireless manner between two or more parts.
Can expect, the setting of the first motor speed sensor 52 and the second motor speed sensor 62 is a kind of mode that revolution detector detects rotating speed, and the rotating speed of other usual manners to the first motor 5 and the second motor 6 can also be adopted to detect.In addition, first motor control module 51 and the second motor control module 61 can also be set, two motor control modules control the first motor 5 and the second motor 6 respectively, and two motor control modules can be connected with controller 1 and two motor speed sensors, as shown in fig. 1.
For realizing course changing control, can prestore in controller 1 activation threshold value turned to, and now, above-mentioned control system can realize course changing control according to the control method shown in Fig. 2:
First can carry out initialization process to program, then perform S10;
S10: activation threshold value is pre-stored in controller 1, then performs S11;
S11: controller 1 receives turn sign, and obtain the rotating speed of motor under current state driving both sides vehicle wheel rotation respectively, namely obtain the rotating speed of the first motor 5 and the second motor 6;
S12: turn sign and activation threshold value compare by controller 1, judges whether the turn sign received is less than activation threshold value, and if so, then turn sign is more weak, does not meet trigger condition, then return S11; If not, illustrate and need to carry out differential steering control, then now directly can perform S18, enter the control program of differential steering;
S18: controller 1 according to the size of turn sign and current rotating speed calculate turn to time two motors needed for rotating speed of target, i.e. the rotating speed of target size of the first motor 5 and the second motor 6, and export and make two motors carry out the instruction turned to according to the rotating speed of target of correspondence;
What can judge chaufeur according to turn sign turns to intention; namely turn left or turn right; and the amplitude size of rotating; reach this target in advance; the speed of both sides wheel meets certain relation; the differential algorithm of both sides wheel according to the speed of a motor vehicle, turn sign can be set up according to theoretical modeling or analog simulation; and between the speed of a motor vehicle of both sides wheel and the rotating speed of motor, meet certain relation; therefore in fact can set up the differential algorithm of the current rotating speed of motor, turn sign, rotating speed of target; and with exist in controller 1 so that controller 1 performs S18.
S19: the first motor 5 and the second motor 6 carry out work according to the signal of the current rotating speed received and rotating speed of target, drive both sides vehicle wheel rotation respectively, perform differential steering action to make both sides wheel.
The instruction of step S18 middle controller 1 directly can export two above-mentioned motor control modules to, and two motor control modules, according to the current rotating speed of motor and rotating speed of target, control two motors respectively and reach rotating speed of target.
When controller 1 does not receive turn sign, then correspondingly handling maneuver stops.Also can in course changing control, using the elimination of turn sign as the clear and definite instruction turning to stopping, as shown in Figure 2, after S19, also perform step S20, when electric control handle is set, controller 1 detects the return signal whether receiving electric control handle, during return, show not need execution to turn to, export without turn sign, now, can stop turning to.
Adopt above-mentioned control system and control method, can be controlled whole steering procedure by controller 1, rotating speed of target when turning to is through accurately calculating, and realize the driving to both sides wheel respectively by two motors, whole steering procedure can both be effectively controlled, therefore its intelligence degree is high, turn to more accurate reliable; And compared to traditional mechanical steering mode, in this embodiment, both sides wheel is in motoring condition all the time when turning to, and namely makes PURE ROLLING, can save energy, also can turn to fast, neatly in Different Ground situation; In addition, because the first motor 5 and the second motor 6 drive both sides wheel to change speed and direction respectively, its controllability is higher, therefore its turn radius can not be subject to uncontrollable factor interference, that is, when controlling both sides wheel differential steering respectively, avoiding the uncontrollable factor that single wheel moves because of force of inertia, thus realizing small radius steering.
Such as, when control system of the present invention realizes pivot stud, control system can control two motors and drive both sides wheel to rotate with same speed, and direction of rotation, finally realize differential steering, Turning radius is now only 1/2 of car load width, and in background technology, the Turning radius minimum value of mechanical steering mode is car load width.
In above-mentioned control system and control method, can S10 be saved, but the setting of step S10, for the triggering turned to arranges a standard.Herein, in order to realize stable turning, and reducing turn radius, this side wheel of electric machine control of non-turn side during differential steering, can be made with the speeds of V+ Δ v, and turn side is with the speeds of V-Δ v, controller 1 can calculate Δ v according to turning to demand and present speed.For improving steering safety pulsation-free object further, the threshold value turned in the manner described above can be set, namely step S10 is performed, during lower than this threshold value, carry out micro-diversion treatments, non-turn side wheel is continued according to V speeds, and turn side wheel is according to the speeds of V-Δ v, to reach micro-object turned to.Certainly, according to the overall walking performance of vehicle, can limit the speed of a motor vehicle, such as, limit vehicle and just can carry out micro-turning to when the speed of a motor vehicle is less than 5km/h.When turn sign is higher than this threshold value, pivot stud can be carried out, as mentioned above.Be appreciated that pivot stud and micro-ly turn to the differential steering also belonging to broad sense.
Can be further improved control system of the present invention mentioned above and control method.
Control system of the present invention may further include braking mode detector 3, braking mode detector 3 is connected with controller 1 signal, whether braking mode detector 3 pairs of bulldozers are in braking mode is detected, and detection signal is transmitted this controller 1, only have when controller 1 receives the signal of non-brake state, controller 1 just performs above-mentioned course changing control.Such as, braking mode detector 3 can detect the signal of brake pedal, or the signal of direct-detection drg.
Can also arrange gear detector 4, gear detector 4 is connected with controller 1 signal, and the gear signal of gear detector 4 pairs of bulldozers detects and by this signal transmission to controller 1.
After the activation threshold value executing S12 judges, can first adopt above-mentioned braking mode detector 3 and gear detector 4 to carry out the detection of braking and range state, its detailed process can be carried out according to the S13-S15 shown in Fig. 2:
S13: braking mode detector 3 detects speed-slackening signal;
S14: according to the speed-slackening signal received, controller 1 judges whether bulldozer is in braking mode, if be in non-brake state, then controller 1 carries out course changing control, directly can perform S18, also can perform S15 further; If the braking mode of being in, then can return step S13, just proceed until be in non-brake state and turn to relevant operation; When being in braking mode, also directly can stop, any response not done to steering operation.
S15: gear detector 4 detects gear signal, and gear signal is passed to controller 1, controller 1 controls accordingly according to the gear signal received, if be in forward gear, then directly can perform S18, and controller 1 carries out course changing control; If be in backward gear, then controller 1 exports and reduces the instruction of running velocity and control both sides wheel respectively to the first motor 5 and the second motor 6, two motor and carry out speed-down action, and then performs S18.
Certainly, when gear detector 4 instruction is in forward gear, controller 1 can not send the instruction of deceleration, also can send the instruction of deceleration, and turn to because bulldozer can realize high pulling torque when low speed, its turn radius can be relatively little; And preferably slow down when being in backward gear, to improve the safety turned to, guarantee to turn to and complete smoothly.In addition, the order that above-mentioned speed-slackening signal detects and gear signal detects can intermodulation, and the sequencing that both there is no execution limits.
Can above-mentioned embodiment shows, using speed-slackening signal as a condition that turn to, first can detect speed-slackening signal, if bulldozer is in braking mode, can not turn to even if controller 1 receives turn sign before turning to.When bulldozer is in braking mode, steering operation cannot carry out smoothly, also can affect safety, therefore speed-slackening signal can be improved as steering condition the safety turned to, and reduces fault and occurs.
It will also be appreciated that, control system of the present invention can also arrange electrical fault detector 7, and electrical fault detector 7 is connected with controller 1 signal, and electrical fault detector 7 can carry out fault detection to two motors, and detection signal is passed to controller 1, so that controller 1 controls accordingly.Such as, controller 1 can install telltale, and the fault of motor is shown, and also can be warned when motor breaks down.Electrical fault detector 7 can detect the fault of motor, can prevent over-voltage and over-current from burning out motor, correspondingly also ensures that two motors can drive both sides wheel to complete in normal state and turn to.
Electrical fault detector 7 can be an independent fault detection element, also a breakdown signal detection module on controller 1 can be mounted in, it can also be the detecting element etc. be arranged on motor, no matter adopt which kind of form, electrical fault detector 7 generally will be connected with two motor signal, thus completes the fault detection to two motors.
For the various embodiments described above, using the control signal of stall signal and rotating speed as the controlled condition that can turn to, as shown in Figure 2, S16 and S17 can also can be increased between S15 and S18:
S16: controller 1 obtains the running velocity of bulldozer, and judge whether bulldozer is in stall condition according to the rotating speed of two motors and the running velocity of acquisition, if not, then directly can perform S18, the rotating speed that also can perform S17 further judges; If so, then can stop, not performing course changing control;
S17: according to the rotating speed of two motors, controller 1 judges that whether the rotating speed of motor is controlled, if motor speed is controlled, then perform S18, if rotating speed is uncontrollable, then can stops, not performing course changing control.
Bulldozer theoretical moving velocity under normal circumstances can be calculated according to the rotating speed of motor, when the actual travel speed obtained is far longer than the theoretical velocity corresponding with current motor rotating speed, show that bulldozer is in stall condition, if perform steering operation, can traffic safety be affected.Therefore, step S16 can improve the safety of steering operation further; And the whether controlled of motor speed can be detected by above-mentioned motor failure signal detection module, also can by controller 1 Direct Analysis.It is multiple that motor is that uncontrollable reference factor has, such as, motor does not rotate according to motor drive module instruction, then motor actual speed does not meet theoretical range, or the distortion of motor speed detection signal, no signal output etc., such situation all can cause motor speed uncontrollable, PWM (pulse duration modulation) value etc. that controller 1 can control according to the cireular frequency of motor, stator speed, motor torque and electric moter voltage, motor speed, guarantee that electric machine operation state meets control overflow, in case motor stall or there is potential safety hazard, impact travels and turns to.When motor speed is uncontrollable, steering operation cannot normally be performed, and namely both sides wheel cannot be made to carry out differential steering according to expection.Therefore, this step S17 can improve the safety of steering operation equally.
Obviously, when turning to, can perform step S16 and/or S 17, the two all performs as preferred version.
Above-mentioned S13-S17 not only can perform according to the order shown in Fig. 2 successively, also can carry out successively according to random order, even some step can be carried out simultaneously: such as, and above-mentioned stall detection and the whether controlled detection of rotating speed just can be carried out by the module of two in controller 1 respectively simultaneously.That is, between above-mentioned S13-S17 and the restriction of out-of-order, it can be arranged between S12 and S18 according to random order.Certainly, above-mentioned S13 and S17 also can selectively perform, or even all will not perform, but the scheme all performed obviously is the comparatively preferred scheme of one.
Please refer to Fig. 3, Fig. 3 is the schematic diagram of a kind of set-up mode of activation threshold value in controller provided by the present invention.
The flip flop equipment that turns to of the present invention can be electric control handle, and by the amplitude judging with corner size to turn to that turns to of electric control handle, and the signal that turn signal detector 2 detects is the corner of electric control handle.Below for electric control handle, the triggering system that turns to of the present invention is briefly introduced: activation threshold value is the S shown in Fig. 2min, activation threshold value can be two end values being in positive pole and negative pole, when the corner of electric control handle is more than or equal to ± Smintime, electric control handle just can trigger steering operation, and namely turn sign is now greater than activation threshold value; It should be noted that, comparing of activation threshold value now and turn sign is the comparison of its absolute value, and namely herein positive and negative only represents direction, does not represent size.Obviously, controller of the present invention can also arrange and turn to amplitude, the S namely shown in Fig. 2max, stop turning to when the corner of electric control handle exceeds and turns to amplitude.
Certainly, the turn sign that above-mentioned explanation only detects for turn signal detector 2 is described for angular signal, when the turn sign that turn signal detector 2 detects is other signals, activation threshold value just becomes other signals accordingly, its principle and operation can be used for reference above, repeat no more herein.
Above the control system of bulldozer differential steering provided by the present invention and control method thereof are described in detail.Apply specific case herein to set forth principle of the present invention and embodiment, the explanation of above embodiment just understands core concept of the present invention for helping.It should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention, can also carry out some improvement and modification to the present invention, these improve and modify and also fall in the protection domain of the claims in the present invention.